In this chapter, the reader is introduced to interfacing of external memory devices with 8051 microcontroller. After completion of the chapter, the reader should be able to understand

  • How to interface external RAM and ROM with MCS-51.
  • Related timing diagrams for external memory access.
  • Security features offered by MCS-51 through on-chip program lock bits.

17.1 | Introduction

As we have completed major discussions on internal architecture and instructions of MCS-51, we now may focus on various interfacing issues related to it. We start with external memory interfacing.

17.1.1 | Need of External Memory

At this stage, the reader may ask about the need of external memory interfacing. As a matter ...

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